Miami Beach, Champlain Towers South apartment building collapse, Part 07 90

[Seppe]

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Previous thread (Part 06)
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https://www.eng-tips.com/viewthread.cfm?qid=485223

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[Spartan5]

The last time MarkBoB2 posted the pictures the hexagonal object with a pole protruding from it was described as “the bottom of a deck table along with the mast for holding the sun shade.” At that time what they had identified as a “water main” in the pictures above they noted as a “rooftop ventilation fan.”

It was also pointed out to Mark that blue paint was used to mark objects to be retained while red designated the presence of human remains. Mark has ignored that.

Look at the link to the NIST recovery area in my link at the top of this page. All blue paint.

 

[Demented]

@Thermopile
Why we're seeing the coating on some rebar. This very likely would be spray galvanizing.

So in essence, the structural repairs in the 90's were injecting some foam into cracks, knocking off loose concrete, painting rebar, and repair mortar? I know repair mortar is 3000k-6000kpsi depending on how long it's been before it dried, but is it actually rated for replacing concrete around reinforcement? This could be what we're seeing in sections of the slab cores that have crumbled and appear to be powder.


Edit: Repair mortar

https://images.thdstatic.com/catalog/pdfImages/10/10c054b7-c99c-4fc0-8849-2ee4a75f1c8e.pdf

Precision guess work based on information provided by those of questionable knowledge

 

[spsalso]

But. You ask who is the ONE person responsible for the safety of a building.

I am more after who was the person who was supposed to inspect the implementation of the structural design.

And, as much as some would like that to be the EOR that just isn't the case.

I think it could have been on these buildings. From reading the Miami Herald article about the Coral Gables building, it does seem so.

A complex building requires the observations and testing of dozens of professionals. I might direct their work but I am not responsible for it. Does that make any sense?

I do understand that the inspector of a project does not have to be the designer. And, in that case, it would be ridiculous to hold the designer responsible for the inspector not catching a mistake. Unless, of course, that inspector was "directly deputized" by that designer as a stand-in.


spsalso

PS. Sounds like you take your work seriously. I like that!

 

[gonefishing2]

@Demented, The permit stuff does not specific where the 20 SF concrete slab was replaced either. Wonder if it was the garage floor?

I saw column rebar that looked galvanized too, which would make you wonder if some columns had very deep repair work done?

I hope MarkBoB2 will post some high resolution pictures, so we can see what he sees.... I can only make out a couple of things from his post, but read the narrative and assumed it was accurate.

@MarkBoB2, Some older Rheem Outdoor AC's and HP's used a rectangular cabinet and the compressor was outside the coil box, but newer Rheem's and all other brands now days have the compressor mounted in the center of the coil box.

 

[Demented]

This "repair mortar" stuff seems to be specifically designed for overhead work.

Contractor logic.
It's $20 a bucket
It requires no mixing.
It says 6kpsi
I can lay up to just over an inch at a time with no form?
It says corrosion inhibiting?

You mean I can pay a laborer $10/h to stand on a bucket (hey, the mortar comes.in a bucket), chip off some concrete, inject some foam, paint the rusted shit, and have him use a putty knife to smear that shit on and shape it?

Count me in!

Precision guess work based on information provided by those of questionable knowledge

 

[gonefishing2]

@Demented,

I saw another permit where concrete crack repair was done with something other than urethane. So this is not the first concrete repair. Appears this garage has been an issue from almost day 1, and the Ocean is not giving up..

 

[gonefishing2]

#Demented, Did the contractor core sample the roof, before work started?

 

[SFCharlie]

then pasted into a PowerPoint document to enable using its powerful zoom capabilities

Could you please attach the PowerPoint file, so we can all zoom in?
(The Image icon destroys any resolution your images had)
Thanks for digging into this...

SF Charlie
Eng-Tips.com Forum Policies

 

[arbitraria]

the person who was supposed to inspect the implementation of the structural design

this was in the "condo structure" permit file from yesterday's uploads.

 

[AutisticBez]

I have watched enough episodes of HVAC to know that you need a crane to move an air conditioning unit. There isn't going to be an air conditioning unit, not bolted down on the roof, because first your crane is going to remove the old one, then position the new one. Or you position the new in a new spot and leave the old, or remove at a later date.

But, your job hinges on booking the crane in. You aren't going to lift it in place then bolt it in the next day. Thats dumb. The suggestion that you'll have random equipment on the roof unbolted is void of reason. Your HVAC guys will work as many hours as it takes to get the job done. Its not a case of 5pm knockoff time, go home, bolt it in tomorrow.

 

[Demented]

@thermopile
The repair work to the 01, 02, 03, 4, 08, 09, 10, 11, and 12 stacks?
This permit raises some eyebrows.


As for core samples of roof, I cannot imagine so. I'll have to dig around but core drilling a roof in the rain season is not something I'd expect anyone to do here.
I feel they would have just followed the print and put all trust in the engineer, and ran the epoxy bolts in where the anchors sat, plus or minus 2" from c to c.

Precision guess work based on information provided by those of questionable knowledge

 

[gonefishing2]

Residential Package Units weight 400-500 lbs. But Outdoor Split Residential Units weight more like 250-300 lbs. for a 5 ton model. There is some variance depending on Brand and thickness of sheet metal they use. What I saw on the roof was residential units for the Condo's and the commercial unit was much larger and heavier.

I have installed many residential HVAC units, and we do it with hand trucks. The package units, we use a custom dolly to roll them off the trailer and move to pad.

Those Split Residential Units could easily come up the elevator

In fact, I used my mother-in-laws residential elevator to take her new HVAC unit up to the attic.....

Engineer by day, and HVAC was side business. In my prime, I was lone ranger on installs and did it all with muscle......

 

[gonefishing2]

@Demented, You must be talking about all the balcony repairs when you refer to those stacks, with the long punch lists for each stack??

 

[Demented]

From around 2002 with the exploratory excavation of columns to find and repair rebar corrosion. I don't have documents in front of me right now though. I could be blurring two things.

Precision guess work based on information provided by those of questionable knowledge

 

[gonefishing2]

And the Conspiracy Plot thickens............

Ah they mention repair of delaminations of balcony's.....

 

[SFCharlie]

PLEASE STOP POSTING IN THIS PART 7 PLEASE
Please allow me to move the discussion to Miami Beach, Champlain Towers South apartment building collapse, Part 08, Thank-you.
Someone Please close this post to new postings, or message me how to do this, Thanks.

SF Charlie
Eng-Tips.com Forum Policies

 

[Demented]

Conspiracy?
*puts on Inconel718 hat*

And yes, I was blurring two things. Dumbdumb over here has to go find what he was referring to with the column exploration. It may not have even been work that was done yet. I got distracted by requirements over piles and core drills in the balcony repair permits and jumped to assumptions.

Because Surfside
​I will post a timelapse soon that shows where the water comes from

​There will be a full moon on Friday. Tune in at 9 am for high tide; and 11 to 1 when the tide is going out. Let's see if the water is higher at 9 than it is at 1pm

The slab really is filling with water with the tides.
This will be interesting.

Precision guess work based on information provided by those of questionable knowledge

 

[MarkBoB2]

At the request of SFCharlie I have uploaded a PowerPoint file with this submission containing the four images shown in my last submission. Hopefully this will improve the resolution of the images. It will also allow removing some or all annotation over the images to permit viewing any objects obscured by the annotation.

For anyone without a PowerPoint application, I suggest copying the JPG or PNG images from my last submission using your computer's COPY function and then pasting the copied image into either a Word or PoserPoint document before viewing. Both of these applications have zoom capability. When I did this on the images from my last submission, the resolution was only slightly degraded, probably because of using the Microsoft Paint application to create a JPG or PNG version of each image. If you still find the image resolution unsatisfactory, then it's likely because your computer display is not good enough.

 

[gonefishing2]

The conspiracy thing was just it seems there have been lots of repairs of damaged concrete on this project over many years, so only a real dull Condo owner, would not realize something ain't right.... All the cosmetic work just covers up the cancer........I think they said one owner was a structural engineer.....

I assume records would show a lot of turn over of owner's over the years...... Some stayed long term, but I would imagine the more savvy ran...

Hard for me to imagine folks in Condo that knew engineers or builders did not ask what they thought of water intrusion.....

 

[spinspecdrt]

There is also what is called structural observation in section 17 of the building code. These observations are performed by the engineer of record. Structural observation is just a periodic site visit. Example, just before pouring the first deck, the engineer comes out and takes a look at it. This is in addition to special inspection and city inspection. Special inspection does not replace inspection by the governing agency.

Structural observation is only required for certain risk categories, seismic areas and high wind areas. I imagine Miami qualifies as a high wind area. I am certain special inspection was not a requirement at the time CTS was built. Structural observation was part of the building code then but that doesn't mean the governing agency required it.

My best guess, Miami, 1980, the developer had just given the city $200,000 for sewer improvements..... I doubt there was meaningful inspection.

It's events like this that occured pre early 1980's that led to special inspection requirements being added to the building code.